Autosave can be improved to real 'autosave' by saving files in progress (being modified) i.e. each few seconds after modification into *internal* PHPEd storage, not to the place they reside.
This will help to combine safety even for online file modifications, where saving original file randomly is undesired, while allowing not to lose work in case of power down or OS/PHPEd crashes.

So.
- Normal 'Save' saves file to the place it should be, removing 'saved' copy afterwards.
- Autosave saves local 'saved' copy, timestamping it.
- In case of unclean editor shutdown, on load modified files can be recovered back from local copies, not from the initial source (maybe with timestamp matching and asking user if the source is newer than local copy).
- Clean editor shutdown removes all local copies just before final shutdown (after user is asked to save modified files).